The disclosed technology relates to corrosion- or rust-preventive coating compositions and methods of their use (rust being considered a form of corrosion). The compositions comprise an oxidized α-olefin, an ester-containing polymer, a carboxylic acid, and a salt of an alkylarylsulfonic acid, optionally with a volatile diluent.
Rust preventive coatings have been known to comprise a mineral (hydrocarbon) wax in a solvent or other liquid medium. Such coatings have been applied to metal surfaces, especially ferrous surfaces, as a rust preventative. They may be distinguished from other types of coatings such as paints in that the wax-containing coatings are often of a relatively temporary nature, imparting rust inhibition over a term of days or perhaps years, and in some instances being removed prior to further treatment of or working with the metal surface.
Coating and anti-rust compositions are known. For instance, U.S. Pat. No. 4,426,229, Bolton et al., Jan. 17, 1984, discloses oxidized alpha-olefin waxes. In an example, an oxidized C30+ alpha olefin is substituted in a floor polish formulation for unoxidized C30+ Alpha olefin and the resulting film was tough and cohesive.
U.S. Publication 2007/0095723, Baralt et al., May 3, 2007, discloses an oxidized olefin wax useful as a pour point depressant in a hydrocarbon composition.
U.S. Publication 2013/0068134, Yang et al., Mar. 21, 2013, discloses oxidized alphaolefins. Oxidized hydrocarbon waxes may have improved hardness or viscosity. The hardness of waxes is said to be a performance criterion in applications such as polishing, coating, and others.
WO 2013/134062, Lubrizol, Sep. 12, 2013, discloses waterborne coatings that provide improved corrosion protection. The composition may include water, a polymer resin component, and a corrosion inhibiting component comprising a first complexing agent comprising a trialkanol amine and a second complexing agent comprising a carboxylic acid.
GB 1 249 144, Esso Research and Engineering Company, Oct. 6, 1971, discloses an organic rust inhibiting composition comprising an aqueous ammonia gelled overbased alkaline earth metal sulfonate, a coating material which is a hydrocarbon polymer resin or a mixture of a hydrocarbon polymer resin, wax, and ethylene-vinyl acetate copolymer, and a hydrocarbon solvent.
U.S. Pat. No. 6,312,509, Moradian, Nov. 6, 2001, discloses a rust preventive coating composition including a microcrystalline wax, naphthenic and paraffinic oils, oils-soluble alkali-metal sulfonate, or other components.
EP 1 038 933, Kawasaki Steel Corporation, Sep. 7, 2000, discloses a coating composition comprising a methacrylic resin prepared by copolymerizing styrene or a substituted styrene, a methacrylic ester, and an olefinic compound having at least one carboxylic group.
It would be desirable obtain a wax for a coating composition which provides very good rust inhibiting performance, including at least one of good film integrity, good salt-spray performance, and few premature failures.